There is suggested a technology of coating a bioactive ingredient for fertilizers, pesticides and the like with a coat film, thereby controlling elution appropriately, so as to cause elution thereof at given period according to the growth of plants.
Recently, enhanced attention is paid to easily degradable resins for thoughtful consideration for the environment. JP 11-130576A and JP 7-505B disclose granules coated with polycaprolactone and polyethylene or the like. With coated granules of fertilizers, however, it is difficult to control elution using an easily degradable resin as a coat film so as to elute a fertilizer component at given period.